1. Field of the Invention
The present invention relates generally to medical treatment of the systemic DNA mutation diseases accompanied with development of somatic mosaicism and elevation of blood extracellular DNA and, more particularly, to a treatment of diabetes mellitus and atherosclerosis.
2. Description of the Related Art
Mosaicism refers to a mixture of cells of different genetic composition in one individual. When DNA mutation is detectable in number, but not all somatic cells in one individual, it is called somatic mosaicism. Development of somatic mosaicism has been recently recognized as important mechanism of systemic DNA mutation diseases progression (Gottlieb B et al., Selection and mutation in the “new” genetics: an emerging hypothesis, Hum Genet. 2010 March; 127(5): 491-501.) Importance of somatic mosaicism involving disease-causing mutations has been reported for variety of monogenic (reviewed by Youssoufian H., Nature Reviews Genetics 3, 748-758, October 2002) and more recently for multifactor DNA mutation diseases: cardiac rhythm disorders (M. H. Gollob et al., Somatic mutations in the connexin 40 gene (GJA5) in atrial fibrillation, N. Eng. J. Med. 354 (2006), pp. 2677-2688.); atherosclerosis (S. De Flora et al., Mutagenesis and cardiovascular diseases. Molecular mechanisms, risk factors, and protective factors, Mutat. Res. 621 (2007), pp. 5-17), systemic vascular disorders (B. Gottlieb et al., BAK1 gene variation and abdominal aortic aneurysms, Hum. Mutat. 30 (2009), pp. 1043-1047); immune deficiencies (Wada T. et al., Somatic mosaicism in primary immune deficiencies, Curr Opin Allergy Clin Immunol. 2008 December; 8(6): 510-4); Alzheimer disease (Beck J A et al., Somatic and germline mosaicism in sporadic early-onset Alzheimer's disease. Hum Mol Genet. 2004 Jun. 15; 13(12): 1219-24.); diabetes mellitus (Emma L. Edghill et al, Origin of de novo KCNJ11 mutations and risk of neonatal diabetes for subsequent siblings. The Journal of Clinical Endocrinology & Metabolism Vol. 92, No. 5 1773-1777).
According to current knowledge the systemic DNA mutation diseases represent very distinct subsets of human pathology different in etiology and pathogenesis and accordingly has fundamentally different, usually palliative treatment modalities—cholesterol lowering therapy for atherosclerosis (New Concepts and Paradigms in Cardiovascular Medicine: The Noninvasive Management of Coronary Artery Disease, K. Lance Gould, THE AMERICAN JOURNAL OF MEDICINE, Volume 104, Jun. 22, 1998, pp. 2-17) and insulin therapy or insulin sensitization therapy for diabetes mellitus (Pharmacological Management of Diabetes: Recent Progress and Future Perspective in Daily Drug Treatment, Gerard Emilien et al., Pharmacol. Ther. Vol. 81, No. 1, pp. 37-51, 1999).
More recently the gene therapy was recognized as potential tool for disease specific intervention which may target the function of certain specific disease involved genes and provide more efficient cure based on repair of existing genetic defects in atherosclerosis (Ishisaki A, et al., Novel ideas of gene therapy for atherosclerosis: modulation of cellular signal transduction of TGF-beta family. Curr Pharm Des. 2006; 12(7): 877-86; Harris J D, et al. ApoE gene therapy to treat hyperlipidemia and atherosclerosis. Curr Opin Mol Ther. 2006 August; 8(4): 275-87; Hayden et al. Gene therapy method for reducing risk of atherosclerosis, U.S. Pat. No. 6,784,162) and diabetes mellitus (G B Parsons, Ectopic expression of glucagon-like peptide 1 for gene therapy of type II diabetes, Gene Therapy (2007) 14, 38-48; L. Chan, In vivo gene therapy for diabetes mellitus, Trends in Molecular Medicine, Volume 9, Issue 10, October 2003, Pages 430-435; M. During, Compositions for gene therapy of diabetes, EP1889914).
However no cure exists which may target the evolution of disease causing DNA mutations leading to development of somatic mosaicism. Accordingly, the development of new effective, non-toxic method that may suppress the development of somatic mosaicism and consequently be effective cure for systemic DNA mutation disease is an extremely important task.
Circulating extracellular nucleic acids were discovered more than 60 years ago (Anker P Circulating DNA in plasma or serum, Clin Chim Acta. 2001 November; 313(1-2): 143-6). However until now elevated levels of extracellular blood DNA in systemic DNA mutation diseases, and in particular in atherosclerosis and diabetes mellitus were considered only as useful diagnostic and research tool (EI Tarhouny S. A. et al., Assessment of cell-free DNA with microvascular complication of type II diabetes mellitus, using PCR and ELISA. Nucleosides Nucleotides Nucleic Acids. 2010 March; 29(3): 228-36; Langford M P et al., Plasma levels of cell-free apoptotic DNA ladders and gamma-glutamyltranspeptidase (GGT) in diabetic children. Exp Biol Med (Maywood). 2007 October; 232(9): 1160-9; Amalich F. et al., Prognostic value of cell-free plasma DNA in patients with cardiac arrest outside the hospital: an observational cohort study, Critical Care 2010, 14; Amalich F. Association of cell-free plasma DNA with preoperative mortality in patients with suspected acute mesenteric ischemia, Clinica Chimica Acta, in press; Zhong S, Presence of mitochondrial tRNA (Leu (UUR)) A to G 3243 mutation in DNA extracted from serum and plasma of patients with type 2 diabetes mellitus 2000 June; 53(6): 466-9.)
Circulating extracellular nucleic acids have never been considered as potential therapeutic target in systemic DNA mutation diseases. Accordingly, no therapeutic method was developed which targets extracellular blood DNA in systemic DNA mutation diseases. Thus it makes impossible to take any technical solution as prototype.
As used in this application, the following terms are meant to have the following corresponding definitions.
Deoxyribonuclease (DNASE) is any enzyme that catalyzes the hydrolytic cleavage of phosphodiester linkages in the DNA backbone.
Extracellular blood DNA number average molecular weight—the number average molecular weight is a way of determining the molecular weight of a polymer. The number average molecular weight is the ordinary arithmetic mean or average of the molecular weights of the individual DNA macromolecules. It is determined by measuring the molecular weight of n polymer molecules, summing the weights, and dividing by n. The number average molecular weight of extracellular blood DNA can be determined by gel electrophoresis. The shift of extracellular blood DNA bands to low-MW areas reflect decrease number average molecular weight and in fact reflects enzymatic cleavage of extracellular blood DNA.
DNA mutation disease refers to diseases where specific DNA mutation has been identified as single leading cause (monogenic or single gene disorders) or multifactor disorders resulting from mutations in multiple genes, often coupled with environmental causes.
Systemic disease is one that affects a number of organs and tissues, or affects the body as a whole.